[PATCH] netpoll: fix incorrect access to skb data in __netpoll_rx
From: Eric Dumazet <hidden>
Date: 2011-08-26 16:26:16
__netpoll_rx() doesnt properly handle skbs with small header pskb_may_pull() or pskb_trim_rcsum() can change skb->data, we must reload it. Signed-off-by: Eric Dumazet <redacted> --- net/core/netpoll.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index adf84dd..5262251 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c@@ -558,13 +558,14 @@ int __netpoll_rx(struct sk_buff *skb) if (skb_shared(skb)) goto out; - iph = (struct iphdr *)skb->data; if (!pskb_may_pull(skb, sizeof(struct iphdr))) goto out; + iph = (struct iphdr *)skb->data; if (iph->ihl < 5 || iph->version != 4) goto out; if (!pskb_may_pull(skb, iph->ihl*4)) goto out; + iph = (struct iphdr *)skb->data; if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) goto out;
@@ -579,6 +580,7 @@ int __netpoll_rx(struct sk_buff *skb) if (pskb_trim_rcsum(skb, len)) goto out; + iph = (struct iphdr *)skb->data; if (iph->protocol != IPPROTO_UDP) goto out;